Pressure-fluid motor



Jan. 19, 1926.

- 1,570,379 G. H. GILMAN PRESSURE FLUID MOTOR,

Filed March 28, 1916 2 Sheets-Sheet 1 I W II I 4 Jan. 19", 1926. v G. H. GILMAN PRESSURE'FLUID MOTOR 2 Sheets-Sheet Filed March 28', 916

1 v \i J if that, the same is adapted tou'se in drilling 1 eludes a cylinder 1 having a rotating mech;

Patented Jan. 19, 1926."

GEORGE n. ermvramor BELMONT; MASSACHUSETTS, iissrernoit'ro SULLIVAN MACHINERY c0MPA1-IY.-a ooaronAr o'n or M s'sAcHUsE'rrs.

rnEssURE-rnmn Moron Application filed 'March 2s, ieias riai m. sas'ialnnenewed March 11, 1924.

T0 allcvhom it may concern! I Be 1t known that I, GEORGE II. GILMAN,

citizen of the United States, residing at Belmont, in. the county of Middlesex and State of Massachusetts, have invented'cei tain new and'use ful Improvements in Pressure-Fluid Motors, of which the following is a full, clear, and exact specification.

Myinvention relates to pressure'fluid motors, and finds one'of its most obvious adaptations in percussive drills and particularly those of the groundhog: type, although it is not limited to use in that connection.

It has among its objects tov provide an im-" proved motor of small cross section wherein the necessity of providing valveslocated at the side'of the same is avoided. A further object of my invention is-ito'provide an improved drill of the valveless type having improved means for controlling the pressure fluid by the movement of the piston, and moreparticularly, improved means for supplying and exhausting the motive fluid. These and other objects of my 5 invention will hereinafter appear. p

In the accompanying, drawings, Ihave, for purposes of illustration, shown oneemr bodiment which my invention may assume in practice. v

In these drawings,

: Figure 1 is an elevation of a drill ofthe ground hog type mentioned above,including its 'nounting, connections,- etc. 7 7 V Figure 2 is a partial longitudinalfsec tional view showing the drill cylinder ,with the piston in itsextreme rearward position the section being taken on line 2 2 of Figure 4. Figure 3 is a view similar to Figure 2, showing the piston in its extreme forward position. 1 1 E ,Figure 1 is a tIflIlVBISG SBCtlOIlfll-VlBW taken on line 4:4 of Figure 2. Figure 5 is; a similarview 5-5 of Figure 2. Figure 6 is a similarview taken; on l ne 6-6'of Figure Q i taken line In the construction illustrated, "I have- 1 shown a ground hog drill. adapted to vertical drilling, it of course being. understood.

This drill inin any desired direction.

anism 2 of any desired form connected ,to

' the upperend'o'f the same, the drill being so su'pported bya'bracket 3 connected to'the casing of the rotating mechanism and. to a trlpod. 4, that the tool 5, the shankjfi of which .extends into a chuck 7, may borea 7 vertical hole b g. enough to receive the cylinder1, asthelatterand the tool are fed to the cylinder and1 also' to a suitable source of pressure fluid supply through a hose9."

.Thecylinder 1, as shown, is connected at its; tool-carrying end, hereinafter called its frontend, through a coarse threadedconnection l0 with the chuck 7 and similarly connected at its opposite, or rear, end .at 11 to a sleeve-likemember 12'threaded into thecylinder, and in turn threaded at its rear end at l3..to the front end of a supply pipe which. may, 1 and preferably does, form a by gravity,-,'a. supply pipe' 8 being connected part of the supply pipe 8. .In the, piston chamber 15 of this cylinder 1, moves a piston 16'preferably provided with-a reduced hammer extension 17 on its front'end adapt ed to move through an opening 18 in the front head of thecylinder'l and strikethe rear. end of the tool shank '6. This piston recelves ltS-- supply of pressurefluid from the pipe8, the latter delivering into-the asshown, substantially halfway through the member '12 and: withina sleeve-like portion 20, the latter} preferablybeing formed sleeve-like member 12 and that member de- V livermg into a tube 19 preferably extending, 85,

9. positely 7 disposedg sleeve 22 of slightly greater-diameter preferably formed on the opposite side of the head from: the sleeve 20 andextending into a bore 23 formed in, i the :piston' 16 when the latter isjin its rearward position shown in FigureiQ. It will sleeve 22,5and having a sliding fit with'the pistonand an ann'ularfl'ange 25 adapted to yform'a seatfor the front end ofjthe sleeve 22 so that the latter may lie'flush with the outer periphery of the portion 24 and the also be noted that thetube 19 gprOjects beyond this sleeve into thebore 23 and is providedwith anlenlarged end 24 preferablyiofjithe same external diameter as the through the same and to the piston bore, preferably passing out of the latter through lateral and preferably parallel passages 26 forming a communication between an inner enlarged chamber 27 at the front end of the bore 23 and a series of lo'ngitudinallyjdisposed grooves 28 formed in the periphery of the piston, these grooves preferably communicating, as shown, with a reduced portion or circumferential roove 29 intermediate the ends of the piston and being disposed on opposite sides of that reduced portion.

hen the piston is in its rearward position shown in Figure 2, air supplied to the piston bore 23 is conducted through these grooves 28 to an annular chamber or groove 30 formed in the inner periphery of the cylinder 1 and leading to the rear pressure surface 31of the piston, so that the air may act on that surface to project the piston forward to the position shown inFigure 2 and drive its hammer portion 17 into engagement with the end of the steel 6. As the piston thus moves forward to strike its blow upon the steel, it uncovers oppositely disposed ports 32 in the front end of the sleeve 22 which communicate with a passage 33 disposed between that sleeve and'the tube 19 and arising from the difference in diameter of the tube and sleeve, mentioned above. Thus the air which has acted upon the rear pressure surface 31 of the piston is enabled to exhaust through these ports 32' and the passage 33 into an'annula-r chamber 34 formed in the rear cylinder head 21, which in turn communicates through a series of rearwardly extending passages 35 with a series of longitudinally disposed grooves 36 formed in the front threaded portion of the sleeve member 12 and communicating with the atmosphere.

As the piston movesforward to strike the tool shank 6, its reduced end 17 of course closes the opening 18 in the front head of the cylinder. Itwill also be noted that the grooves 28 are thenplaced in co1nmunication with an annular chamber or groove 37 in the front end of the cylinder. Thus, obviously, since the piston is constantly connected to the pipe 19, air from the pipe 8 will, in that position of the piston, be delivered to the front end of the cylinder so that it may act on the front pressure surface 38 of the piston and return, the latter from the position shown in Figure3 to the initial position thereof shown in Figure 2. Obviously, as this occurs, the air which has acted expansively to return the piston will also be free to exhaust through the opening 18 in the front of the cylinder, suitable laterally disposed exhaust passages 39 also preferably being provided therefor, so that the .air may find its way into the drill hole and through suitable cooperating longitudt' dinally disposed grooves 40, provided in the outer periphery of the cylinder, pass outward to the atmosphere.

From the above description it is believed to be apparent that air from the tube 19 will be again supplied through the grooves 28 to the annular groove 30 shortly after the piston starts on its rearward stroke. Thus, it will be noted that this air is enabled to act upon the rear pressure surface 31 of the piston and cushion the return stroke thereof, thereby reducing the danger of breakage of the rear head 21. It will also be noted that to supplement this cushioning effect, I have, ashcrein shown, provided a spring 411 coiled about the sleeve 20 on the head 21, and disposed in a chamber 42 formed in the front end of the sleeve 12, this spring acting between thesleeve 12 and the head 21 to absorb any, blows struck the latter and to force the same to itsfinormal position wherein an annular 'fla'nge 43-tl1ereon engages one or more annular washers 14 disposed between the same and a, corresponding flange 45 formed on the cylinder. It will be obvious that by changing the thickness of this washer or substituting a plurality therefor, the position of the head 21 with respect to the cylinder maybe adjusted as desired in order to vary the point in the piston stroke at which exhausttakes place and to vary the size of the piston chamber.

In the operation of'the device shown'herein for purposes of'illu'stration, the drill steel normally rests against the work and is rotated by the rotating mechanism 2. Briefiy reviewing the operation of the means for controlling'the air, above described, it will be noted that when the air is admitted through the tube 19, it passes through the grooves 28 and acts upon the rear pressure surface 21 of the-piston to drive the same 7 forward to strike the steel shank 6, and is thereafter exhausted through the "ports 32, the passages'33, etc. and grooves-36, to the atmosphere. After the piston has thus been driven forward to actuate the tool, the air passing through the grooves 28 and the grooves 37 also acts to return the piston through its action on the front pressure surface 38 thereof, this air thereafter exhausting through the opening 18, passages'39, and grooves 40. As brought out above, air is also admitted to the groove 30 duringthe latter part of the return of the piston, in such a manner as to cushion thelatter on its return stroke and cooperate with the spring 41 in order to prevent breakage of the head 21; lfn my improved construction, it willbe noted that the pressure fluid which drives the piston forward is supplied and exhausted from the cylinder through axially extending passages disposed in the rear end of the cylinder, so that the device may be parent to those skilled. in the art. I V

NVhile I have in this application'specifif made of exceedinglysmall cross section and without it being necessary toprovide any ports or openings in the periphery of thecylinder or any lateralconnections, thereby adapting it to use in various relations and making it especially valuable in connection with adrill of the ground hog type Wherein it is desirable to reduce the cross section of the hole as much as possible and wherein" a side exhaust is unsatisfactory for obvlous reasons. Attention is alsodirectedto the improved results obtainable as a result of the provision of my improved means for; cushioning the piston, and to the simplified constructmu' presented whereby the cost of production of the, device is minimized; These and other advantages of my improved construction will, however,'be clearly apcally described one embodiment which my invention may assume 1n practice, 1t isto be understood that this form of the same'is,

used only for purposes of illustration, and that the invention is in no wise limited thereto,but maybe modified in various ways and adapted to other devices without departing from its spirit, it beingmy intention to inelude all such modifications within the scope 4 of the appended claims.' a

What I claimqas new and desire to secure by Letters Patent is: V l. A fluid motor comprising a cylinder, a piston reciprocable therein, and operating means therefor including coaxially disposed supply and exhaust passage formingm'eans within said cylinder for the fluid acting therein and betweenwhioh and said piston relative movement occurs, said exhaust passage means discharging mosphere. r

2. A fluid motor comprising a, relatively stationary cylinder, a piston reciprocable therein, and operating means therefor ineluding coaxially disposed supplyand ex directly to the =at-' haust passages within said cylinder and be-' tween which and said piston relative movement occurs for the fluid acting in the rear end of said cylinder, said exhaust passage dischargingdircctly to the atmosphere.

3. A fluid motor comprising a cylinder, a piston reciprocable therein and normally" movable relative to said cylinder, and operating means therefor including coaxially disposed supply and exhaust passages within said cylinder and between which and said piston relative movement occurs for the fluid acting in the rear end of sald cylinder, said i exhaust passage discharging directly to the atmosphere. r

4. A fluid motor comprising a cylinder, a

a piston rcciprocable. therein, and operating f means therefor including coaxially' disposed supply and exhaust passages within said cylinder and between which and said piston atmosphere.

relative movement'occurs forthe fluid acting i in the rear end of said cylinder, saidvexhaust passage dischargingdirectlyto the atmosf phere. an fluid motor comprising a cylinder, a

piston reciprocable therein, and operating means therefor including coaxiallydisposed supply and exhaust passages ,lwithin; saidcylinder and adaptedito have sliding telescopic engagement with said: pistonforthe' fluid acting in the rear end'thereofljsaid ex-i haust passage dischargingdirectly to the 7 A fluid motor comprising a cylinder, a

piston reciprocablel therein, and operating posed supply and exhaust passage; means;

means therefor includingconcentrically dis within said. cylinder and betweenwhich and said piston relative movement occurs for the fluid acting in the rear end-ofsaid cylinder.

8. Ajfluid'motor comprising a cylinder, a piston. reciprocable therein, and operating means therefor including concentrically adisposed axially extendingsupply and exhaust passage means within said cylinder and be.- tween which-"and said piston relative movement occurs for the fluid acting in the, rear of said cylinder. 7 1

, 9'. A fluid motor-comprising a cylinder and a piston reciprocable therein, said motor having supply and exhaust passage means within said cylinder and between which and said piston relative movement occurs for the fluid acting inonefend of said cylinder, one of said passages being located within the other, and said exhaust passage discharging at the aforesaid en-d'o'l said cylin-' der. 7

,10. A fluid motor comprising acylinder and a piston reciprocabletherein, saidnio;

tor having supply. and exhaust passage means within said cylinder and between which and said piston relative movement occursv for the fluid acting in one end of ion said cylinder, one of said passages being located withinithe other, and said exhaust passage, discharging directly to the atmos- 'phere. I

I 11. A fluid'motor comprising a cylinder, anaxially bored piston therein, a fluid supply tube extending into the boreofsaid pistonv and having sliding telescopic relation with the latter, cooperating means for distributing fluidfor reciprocating said piston,

and concentrically dispose-d axialh, extending means encircling said tube for conduct:

ing away the exhaust from the rear end of said piston, said means discharging directly to the atmosphere.

12. A percussive tool comprising a cylinder, an axially bored piston therein, a fluid supply tube extending into the bore in said piston, cooperating means for distributing fluid for reciprocating said piston, and a sleeve disposed between said tube and cylinder provided with a longitudinally disposed exhaust passage and having'an exhaust port therein controlled by said piston.

13. A percussive tool comprising a cylinder, a rear head therein, an axially bored piston movable in said cylinder, a supply tube extending into said piston through said rear head and relative to which said piston is movable, cooperating means for distributing fluid for reciprocating said piston, and a sleeve of greater diameter than said tube enclosing the latter and communicating with the atmosphere and the rear end of said cylinder.

14:. A percussive tool comprising a cylinder, a rear head therein, an axially bored piston movable in said cylinder, a supply tube extending into said piston through said rear head, cooperating means for distributing fluid for reciprocating said piston, and a sleeve of greater diameter than said tube enclosing the latter and having exhaustports therein controlled by said'piston.

15. A percussive tool comprising a cylinder, an axially bored piston reciprocable therein, coaxially disposed supply and exhaust tubes extending into the rear end of said cylinder and the bore in said piston relative to which the latter is reciprocable, cooperating means for distributing fluid for reciprocating said piston, and supplemental means for discharging the exhaust from the front end of said cylinder.

16. A percussive tool comprising a cylinder, an axially bored piston movable therein, a supply tube extending into said cylinder having a body portion and an enlarged end extending into the bore in said piston, cooperating means for distributing fluid for reciprocating said piston, and an exhaust sleeve enclosing the body portion of said tube and having the flow therethrough controlled by said piston.

17. A percussive tool comprising a cylinder, a. rear head therein, an axially bored piston movable in said cylinder, a supply tube extending through said head into said piston, means controlled by said piston, for distributing fluid for reciprocating the same, a sleeve enclosing the rear end of said tube, and means disposed between said sleeve and head for cushioning a return stroke of said piston.

18. A percussive tool comprising a cylinder, an axially bored piston in said cylinder, a supply tube extending into said piston bore, means for distributing fluid for reciprocating said piston and conducting pres sure fluid to one endthereof to cushion a return stroke thereof, and supplementary resilientcushioning means cooperating therewith.

19. In a percussive fluid motor, a cylinder, fixed and slidable heads therefor, an axially bored piston movable between said heads, an exhaust member extending from said slidable head into the bore in said piston, means for reciprocating said piston, and

ieans for limiting the movement of said slidable head longitudinally of said cylinder.

20. In a percussive fluid motor, a cylinder, fixed and slidable heads therein, an axially bored piston movable between said heads, an exhaust member extending from said slidable head into the bore in said'pi ton, means for reciprocating said piston, means for adjusting said slidable head longitudinally of said cylinder, and resilient means normally resisting movement of said head in one direction.

21. A fluid motor comprising a cylinder, a rear head therein, an axially bored piston in said cylinder having front and rear pressure surfaces, concentrially disposed supply and exhaust tubes extending through said head into the bore of said piston, means for alternately conducting pressure fluid to said pressure surfaces, and cooperating resilient means for cushioning a return stroke of said piston.

22. A percussive tool comprising a cylinder having a slidable rear head, an axially bored piston in said cylinder, a supply tube extending through said head and into the bore in said piston, means for distributing fluid for reciprocating said piston, a sleeve enclosing the rearend of said tube and ex- 4 tending into said cylinder to a point adjacent said head. and a coiled spring disposed between said sleeve and head.

23. A percussive tool comprising a cylinder, a rear head having ports therein, an axially bored piston in said cylinder, a supply tube extending through said head and into the bore in said piston, means for dis tributing fluid for reciprocating said piston, and a larger exhaust tube enclosing said tube and communicating with the ports in said head, the flow through said exhaust tube being controlled by the movement of said piston.

24. A valveless tool comprising a cylinder, an axially bored piston movable therein, a supply tube extending into the bore in said piston, means controlled by said piston for supplying pressure fluid alternately to the opposite ends of the same, and axially disposed means for exhausting the pressure fluid from the opposite ends of the cylinder in opposite directions.

r w s 1 Q5. fluid' mot'or comprising a: cylinder, an axially bored piston movable-therein, a

supplyf tube extending into the bore in said 'p1ston,'m'eans controlled l ylSilld piston for supplying pressure fluid alternately to the opposite ends thereof, and axially disposed means between which and said piston relative movement occurs and extending into the latter in one posltlon thereof for conductlng away the exhaust. f 7

r 1 26. A fluid motor comprising a cylinder,

fan axially bored piston movable therein, a supply tube extending intothe'bore in said piston and between which and said piston relative movement occurs, means controlled said plston for supplying pressure fluid alternately to the oppositefends thereof, and

axially disposed meansextending into said piston in one positionthereof and; disposed concentrically with said tube "for'conductlng away the exhaust.

27; A fluid motor comprising-a cylinder,

an axially bored piston movable therein, a

supply tube extending into said 'pistonlhaving an enlarged delivery end, means .con-

trolled-by said piston "and betweenwhichand said piston relative movement occurs for supplying fluid delivered by said tube to oppositeends of said piston, andanjexhaust discha-r ing T member '"disposed concentrically wit said tube and extending to a point adjacent the delivery end thereof.

28; *A fluid-[motor comprising a cylinder,

an axially bored piston movable therein, a

supply tube extending into said Piston having an enlarged deliveryxend, means controlled by said piston for supplying fluid'delivered by said tube-t0 opposite ends of said piston, and an exhaust discharging member fluid for reciprocating the same in said cyl-v' disposed concentrically with said tube and extending to a point adjacent the delivery end thereof and having a port .thereincontrolled by said piston.

29. A percussive tool comprising alcylin der, a rear head disposed within the rear end thereof having a rearwardly extending" sleeve, an axially bored piston in saidcylinder, a supply tube extending through said head into the bore in said piston, means controlled by said piston for distributing der, a rear head carried therein having oppositely disposed sleeves thereon, and axially bored piston movable' in said cylinder,

a supply tube extending through said head and sleeves :and into the bore in said cylinder, mearns controlled by said piston for alternately conducting pressure fluid to the -opposite ends'thereof, o6pera i g-mean or .conducting'the exhaust from oneel'l dofsaid cylinderbetweenone of the, sleeves on v Said head and said supply tube, andjcommunica-t ingi 'means forItonducting the same axially between the other sleeve and said cylinder.

supply u tube; exten'ding'therough said head andsleeves" and into thebore insaid cylinder, means controlled by said piston for al ternatel conducting pressure fluidto'the oppositeiends thereof, cooperating means for 31'. ereus'sive'=to:1, comprising a .cylinder, arear head carried therein havingloppositelyldisposed sleeves thereon, an axially bored-piston movable in saidcylinder, a

conducting the exhaust from-Tone end of 1 sa-ideylinderbetween one, of; the sleeves on said 'head a-nd said supply'tube, c ommuni{-' I eating:me'ans'for.. conducting thesameaxially 3 between the rotherfsleeve and saidfcylind'er,

a- 'sleeveg like' supply member communicating tioned 'an d said-cylinder;

32; in. a percussive tool; a cylinder, I an I axially bored piston movabl'e'thereima' slidable rear head carried in} said cylinder and j having 5a port 'therein; a. sleeve fixedto said 'headand ext ending'into the bore in saidpiston inone position thereof and havinga p'aston and through said sleeve, cooperating .means :tor reciprocating said piston in'said cylinder relative to said tube and sleeve, a member attached to the rear end of said cylinder having a longitudinally disposed groove communicating'with the port in said. head, and resilient means disposed between said head and last mentioned member; 1

33. In a percussive tool, a cylinder, an axially'bored piston movable therein, a slidable rear head carried in said vcylinder and having aplur'ality of ports thereirna sleeve fixed to saidhead and extending'into the ,bore insaid piston in one position thereof and having'passages communicating with the, ports in said head, a supply tube extending.

into saidpiston and through said sleeve, co-

operating means for reciprocating said piswith ithe rearend' offsajidtube,anda' spring 7 I acting between the same' 'and 1 said head and-- disposed ;between"--*the fother sleevef memsage commu nicatingf with the port *infsaid head, a supply tube extending into said 'pisliO ton in said cylinderrelative to said tube and sleeve, a member attached to the rear endof said cylinder having a series of longitudi-V nally disposed grooves communicating with the ports in'said head, and resilient means disposed between said head and said last i mentioned member and encircling the rear end ofsaid tube. i V

7 34:.-'A fluid-motor comprising-a cylinder," a piston reciprocable therein,v said piston. having an internal chamber, and a fluid supply conduit fixed with respect to said cylinder and communicating at its endwith said chamber'ln all posltions of saidplston, said motor having-a fluid passage communicating With-said cylinder in the rear of said piston and controlled by the relative position of said piston and conduit,

35. A fluid motor comprising a cylinder, a piston reciprocable therein, said piston having. an internal chamber, and operating means therefor including a fluid supply conduit fixed with respect to said cylinder and communicating at its end with said chamher in all positions of said piston and an exhaust passage within said cylinder for the fluid acting in the rear end thereof, said exhaust passage being controlled by the position of said piston and discharging independently thereof.

36. A valveless fluid motor comprising. a stationary cylinder, a hollow piston reciprocable therein, said motor having fluid distribution means comprising a fluid supply tube between which and, said piston relative movement occurs and carried by the cylinder and projecting longitudinally thereinto, said tube being constantly connected during operation of the motorwith live fluid pressure, and-supplying the same to-the inferior of: saidpiston for distribution thereby to effect; reciprocation thereof, and being provided at its exterionwith means to; conduct away the exhaust from one end of said cylinder.- y t I p I 37 A; fluid motor comprising. a cylinder, heads thereon, apiston reciprocable in said cylinder, said piston having an internal chamber, and fluid distribution and exhaust means for said motor comprising fluid supply and exhaust passage forming tubes pro jecting into said cylinder from one head thereof, one of said tubes having its freeextremity so positioned as to remain within said internal chamber during movement of the piston relatively to said tube, another of said passage forming tubes surrounding ing means for the motive fluid, said passage forming means projectingwithin said cylinder and between which and said piston relative' movement occurs.

3.9. A fluid motor comprising relatively movable cylinder and piston members, and

operating means therefor including; coaxially disposed supply and exhaust passage forming means for the motive fluid, said passage forming means having telescopic sliding relation with said piston.

In testimony whereof I aiflx my signature.

GEORGE H. GILMAN. 

